Appliance to handle shortening

ABSTRACT

Apparatus for managing melted shortening or lard for deep-frying purposes includes an upper tank holding melting elements and a lower tank for receiving melted fat, and a delivery pump, hose, and hand-held nozzle. Tanks are electrically heated and regulated. The melting elements have a large surface area and are designed to present the block of fat with a wide contact area of heated metal. The apparatus can be cleaned by boiling water within the lower tank. The mobile apparatus can be moved about a kitchen in order to load a cooking vessel with shortening and also includes collecting elements to receive used fat from underneath, or to pump from the cooking vessel.

FIELD

This invention relates to apparatus for melting and holding fat, oil,shortening or lard for cooking purposes; also apparatus with acapability to receive and clean melted fat from cookers, with particularrelevance to the fast-food industry.

DEFINITIONS

We use the term “shortening” to refer to any of the group: cooking oil,shortening, fat or lard used for deep-frying cooking purposes.

BACKGROUND

In a kitchen such as a fast-food restaurant where deep-frying ispractised, a number of tasks involving handling bulk shortening (alsoknown as fat or lard) are frequently undertaken. These tasks include:

1. Melting a new block of shortening (it may be 22-44 lb in size).

2. Holding the melted shortening in a tank ready for dispensing intocookers.

3. Dispensing the hot shortening into a hot cooker operating attypically 340-375 deg F.

4. Receiving already melted shortening from cookers for cleaning andeventual return.

Clearly those procedures involving oil do not require a melting step anddo not include the risk of dropping a large (up to 50 lb) perhapsslippery mass into hot melted shortening. Williams et al (U.S. Pat. No.6,330,852) state that “burns are commonplace in high volume foodpreparation establishments some of which lead to permanent disfigurementand disability”. In more detail the usual tasks are:

Task 1: It has been a problem to take a solid block of shortening,typically each block weighing about 25 lb, melt it (which can take aboutan hour and a half), and safely transfer the molten shortening into acooking vessel such as a deep fryer, which is probably in use at thetime. Simply placing the solid block into the cooker and waiting for itto melt is inadvisable because the flow of cooked product to thecustomers is interrupted.

Task 2: it has not been usual to be able to hold the shortening inliquid form in a tank able to be moved about. For instance there aresafety aspects involved; risk of burning people, and risk of fire, aswell as contamination aspects.

Task 3: In the past the melted shortening might be lifted in a saucepanor deep container of 10-20 litres capacity up to the hot fryer andtipping in some or all of the contents. There are significant risksassociated with spilling the molten shortening, which is definitely hotenough at perhaps 250 deg F. to burn workers' skin, onto such as nakedflames, or into water, when it may spit hot shortening and water about.The hotness of the contents may cause the person to be forced to dropthe container.

Task 4: After extended use the cooker may need to have the fat removedagain. There are single-purpose devices to receive hot shortening fromcookers exist but the hot liquid has to be handled several times, andkept hot, before it can be returned to a cooker.

Any solution to the problem of handling bulk shortening should becost-effective, safe, convenient, and hygienic. It is also desirablethat it be “foolproof” in operation because of the likeliness of onlylimited training for operators and the ramifications of unintendedspillage and of an industrial accident type of injury.

Prior-art patent documents have not emphasised the versatility envisagedin providing a device capable of serving the above functions in anexisting kitchen. Hartzog (U.S. Pat. No. 3,466,997) provides a complex,integrated pressure cooking system for chickens using hot fat, includingmeans to receive a block of solid cooking fat 92 into a tray with athermostatically controlled heating coil below. Melting of solidshortening is mentioned in the background of Shumate et al, but is notdealt with in any of the following citations, which assume the use ofcooking oil. U.S. Pat. No. 5,249,511 Shumate et al describes apermanently installed piping in a kitchen, running between the cookers(where it terminating in a flexible hose and valve) and a distributionand waste removal system. This involves a piping installation cost andan obligation of maintenance, and has the disadvantage that pipes willhold cold oil between operations. Grob et al in U.S. Pat. No. 4,974,501provides a deep fat frying apparatus having two frypots and internalmeans for securely collecting and filtering used oil into anunderneath-nesting collection pan. The cooker and the pan haveindependent sets of wheels so that the pan can be taken to a disposalsite if the oil is to be discarded. A filtration system is built intothe pan so that no extra floor space is required, but a special cookeris required. Bizard (U.S. Pat. No. 6,666,131) provides a similar device.Davis et al in U.S. Pat. No. 5,617,777 describe a similar though moreautomated cooker with integral collection. Dirck (U.S. Pat. No.5,823,097) describes a wheeled, low-height (for gravity drainage) oilcollection tank including a heater, filtering means and grinding means,for use with most types of cooker. Williams (U.S. Pat. No. 6,330,852)provides a mobile, heated oil handling system for taking oil to andfilling an adjacent cooker and later pumping out the used oil forfiltering and return, or for transfer to a disposal tank: alsomentioning solid shortening in the background but again providing nomeans for melting it.

OBJECT

It is an object of this invention to provide improved apparatus for themelting, handling, storage and transfer of shortening about cookingfacilities, or at least to provide the public with a useful choice.

STATEMENT OF INVENTION

In a first broad aspect this invention provides a powered appliance toservice deep-fry cookers in a kitchen with a supply of liquid shortening(as herein defined) from time to time, and remove used liquid shorteningfrom time to time, wherein the appliance includes internal means formelting a block of solid shortening, means for holding the meltedshortening in a first internal heated chamber, and means for filling acooker with the hot, melted shortening from the first internal heatedchamber: the appliance also being provided with wheels so that it can bepushed up to the cooker to be serviced.

Alternatively the appliance comprises heated, mobile apparatus forsupplying melted fat, shortening or lard for cooking purposes; whereinthe apparatus includes at least one upper contained area holding meltingelements capable of melting a solid block of shortening and at least onelower internal tank for receiving shortening in liquid form.

Preferably the internal means for melting a block of solid shorteningemploys a series of transverse bars forming a top surface for theinternal heated chamber, each bar being internally heated and capable ofbearing a solid block of shortening during a melting process.

A preferred element used to melt the fat comprises an array of upwardlydirected, narrow-tipped, internally heated metal members havingsufficient mechanical strength to bear the weight of a block of fatplaced upon the narrow tips; so that in use the narrow tips melt theirway towards the centre of the block and thereby apply heat throughoutthe block and melt the block more quickly and so that the heatingelements present a larger heating surface area than that of a flatplanar surface.

In a first related aspect each bar is heated by at least one internallylocated electric resistive element.

In a second related aspect each bar is ohmically heated by passage of aheavy current at low voltage through the surface material of the bar.

In a third related aspect each bar is ohmically heated by circulation ofeddy currents within the bar, the currents being induced by analternating magnetic field developed in proximity to each bar.

Optionally each melting element has a rectangular cross-section ratherthan a triangular cross-section.

Preferably the apparatus also includes a flexible hose connected to apowered pump adapted for the transfer of melted shortening into acooker.

Preferably the flexible hose is terminated in a hand-held nozzle.

In a second broad aspect the appliance also includes means to receivehot used, molten shortening from below a cooker into a protruding heatedcontainer placed for the purpose at a low height above a floor, theappliance including a pump to lift the used shortening from theprotruding heated container into an internal tank: the appliance alsobeing provided with wheels so that the protruding heated container canbe pushed under the cooker to be emptied.

Preferably the apparatus includes means for at least partiallyreconstituting the used melted shortening; such means including withoutlimitation (1) physical filtering means, (2) chemical filtering means(such as activated charcoal), (3) gravity-settling separation means, (4)flotation purification means (such as using bubbles), or (5)centrifugation, along with means to physically dispose of contaminants.

Preferably the appliance includes a second internal heated chamberreserved for handling of used shortening: the first internal heatedchamber of the appliance being reserved for use with new shortening.

In a related aspect the appliance includes a filter through which theused cooking oil is received so that filtered detritus may be removedfrom the used shortening and discarded, so that the shortening may bere-used if acceptable.

The preferred heating means is electricity, alternatively the heatingmeans is a flammable gas.

Preferably the or each internal tank is electrically heated by means ofelectric elements and preferably the temperatures are regulated.

Preferably the internal tank and related parts of the apparatus can becleaned by a process of boiling water within the tank.

Preferred Embodiment

The description of the invention to be provided herein is given purelyby way of example and is not to be taken in any way as limiting thescope or extent of the invention.

DRAWINGS

FIG. 1: is a diagram showing an exterior view of the apparatus ofExample 1.

FIG. 2: is a diagram showing a sectional view through part of an arrayof the fat melter elements.

FIG. 3: is a diagram showing some alternative fat melter elements.

FIG. 4: is a diagram showing another way to heat the fat melterelements.

FIG. 5: is a diagram showing alternative rectangular-section fat melterelements.

FIG. 6: is a diagram (Example 2) of an appliance including fatcollection means.

FIG. 7: is a diagram showing detail of the fat collection means.

FIG. 8: shows another tray mounting means.

EXAMPLE 1

This Example (see 100 in FIG. 1) provides a movable appliance for:

1. Melting a new block of solid shortening (it may be from 20 to 50 lbin weight). (If oil is the starting point then melting is of course notrequired).

2. Holding the melted shortening in a heated tank ready for dispensinginto one or more cookers.

3. Pumping melted shortening into a dispensing pipe and into a cooker.

4. Receiving used, melted shortening from cookers for cleaning, sievingthe solids from the shortening which is held in the heated tank, andeither returned to cookers or to a disposal tank if the shortening isnot required for re-use.

(Optionally a second heated tank is provided for receiving usedshortening, so that new shortening and used shortening are keptseparate).

This invention comprises apparatus for supplying (meaning: first meltingfrom the solid, then holding and supplying as a liquid) fat, shorteningor lard for cooking purposes in premises such as a kitchen where deepfryers or the like require significant amounts of shortening to beprovided for replenishment of their vats. The food being cooked absorbssome shortening. Over time, contamination of the shortening withfragments of food, carbonised material, and thermal degradation meansthat rejuvenation by filtering or replacement of the shortening will berequired.

The apparatus 100 has an outer case 101 (preferably made of stainlesssteel and lined with thermal insulation) which includes at least oneupper area in the form of an enclosed box 103 with an open floor andwith a lid 102, the box surrounding the melting elements 202 (see below)that may have an optimised shape for promoting the speed of melting atypical 27 lb block of fat, placed at about the position of label 103 inFIG. 1, in about 20 minutes. Fat is a poor conductor of heat. Heat inputis required in order to overcome the latent heat of fusion. Once melted,which occurs at a temperature of about 110-180 deg F., the liquid fatflows downwards into a lower, heated tank 105 in which it is kept moltenat a temperature of about 180-250 deg F. Preferred “particular shapes”of the melting elements having narrowed tips 201 (which may be points orelongate ridges) is adapted to melt its way into the block of fat sothat the distance that heat must travel through the block is reduced.Furthermore the shape of the elements increases the total contact areawhich comes into effect more and more as the block of fat continues tomelt over the elements and sag into the intervening spaces. On the otherhand a simpler cheaper shape such as a square bar (501-FIG. 5) holdinginternal heating means is adequately effective.

The weight of the block keeps the block in close contact with theelements. The melting elements 201-202 may be made of stainless steelsheet, folded and then welded together, (as is generally required infood-handling apparatus) and preferably an electric bar type heaterpasses along the interior. The upper box 103 and elements may be largeenough to accommodate two blocks of fat at one time.

The preferred electric element 202 comprises at least one, andpreferably more than two elongated members (as shown in cross-section inFIG. 2) mounted horizontally and having a working area that istriangular in cross-section; a vertex of the triangle being directedupwards (when in use) so as to form an upper narrowed contact surface,the elongated member having sufficient mechanical strength to bear theweight of a block of fat placed upon the narrowed contact surface. Othertypes of heater could make use of internal optionally wicked oil orother fluids as heat transfer agents and could be in the form of aplurality of vertically directed rods, but the preferred version issimpler and is not likely to release a heating fluid into the food-gradefat being melted if a seal should break. Both tanks are electricallyheated by means of electric elements and preferably the temperatures areregulated. We prefer to use electric heating in this machine because ofthe fire risk of heating by flame, and because regulation and controlcan be managed more effectively by built-in means, suitable for use byunskilled operators. The machine can perform adequately using asingle-phase AC mains supply, outlets for which are generally rated at2500 VA maximum. (Three-phase outlets are rare and the internal controlsrequired are more complex). Thermostatically controlled operation withmore powerful heater elements allows the bars to reach a workingtemperature faster and hold that temperature closely, as compared toproviding weaker heaters that are run continuously. A number of suitablethermostats are well known to those in the electrical trades.

The intention is that an unskilled operator can switch the machine on,put a block of fat in with no risk of splashing hot shortening, closethe door, and do some other task(s) while the apparatus converts thesolid block into molten shortening ready for delivery through thedelivery hose without further attention. Preferably the upper box canhold two 27 lb blocks of fat at one time. Other sizes may be moreconvenient for other applications.

The lower tank (or container) 105 also has heating means 106 appliedabout its exterior in order to maintain the contents in a molten state,and typically this heating means is another electric element, regulatedat a temperature sufficient to keep the fat molten even while it isbeing passed through a flexible delivery hose 108. The power rating ofthis element 106 is determined largely by the quality of the thermalinsulation of the lower tank, but 500 VA would usually be sufficient. Ina cleaning mode this element is used to boil a charge of water includinga cleaning agent—surfactant or emulsifier—placed in the or each lowertank.

The apparatus also includes a flexible hose adapted for the transfer ofmelted fat. The outside of the hose is thermally insulated. The hose mayinclude resistive heating elements within its wall in order to maintainany fat within in a melted state. Also, the delivery nozzle 110 shouldbe hung up when not in use so that any fat within the hose can drainback into the system. The flexible hose 108, which is typically about1.5 metres long, is terminated in a hand-held nozzle 110 having an exitvalve. The hand-held portion 109 of the hand-held nozzle is alsothermally insulated so that an operator can maintain a grip when thenozzle is in use without being burnt by the heat of the internal fat, orotherwise being forced to drop the delivery nozzle. There is anelectrically driven pump 107 at the base of the hose, to force the fatout through the nozzle when the valve is held open. A preferred type ofpump is a gear pump, (well known in the relevant arts)using metal gears,and is tolerant of possible solvent effects of molten fat. A returnvalve prevents pressure build-up at the pump outlet. A built-inrechargeable battery to power the pump is a useful feature, because themachine is moved away from its normal place to service a cooker and amains power source requires a power cord to the nearest outlet.Alternatively a hand pump may be used, such as a foot-operated pump.Preferably the apparatus is provided with robust wheels 104 (some aresteerable) and a handle 608 so that it can be pushed about a kitchen inorder to approach a cooker and service it.

FIG. 3 shows cross-sections through some alternative melting elements.301 (at left) indicates the straight sides of a first version that alsoincludes three internal heaters such as 302 and 303. 201 is the uppertip. The version in the centre, 304, is a version with 240 curved sides,which should be stronger for a given thickness of stainless steel. Thisone includes to-and-fro rods of a resistance heater 306 near the tip201, supplemented by further heaters near the base. The heating methodof FIG. 4 leads to a desire to minimise the wall thickness so thatgreater electrical resistance per unit length is achieved, which isconvenient. The right-hand cross-sectional outline 307 lacks internalresistance elements because the skin itself is the heater. This versionalso includes a dependent edge or ridge 308 intended to help the meltedfat drip from the element (something that all versions may use). Notethat all heating elements are relatively closely placed to neighbouringelements so that solid, un-melted fat does not escape from the first box103 into the second box 105.

FIG. 4 shows an optional way to heat the melting elements at the elementsurface itself by the passage of low-voltage, high-current ACelectricity (350 A for example) through the length of theseries-connected array of shaped heaters 400. In FIG. 4, 401 is aconnector to a controlled mains input, possibly including a regulatorfor controlling the heat, 402 represents a step-down transformer ratedat typically 500 to 1000 VA or more, and with a low-voltage output ofperhaps about 2 to 12 volts, driven from the local single-phase mainsvoltage (typically 100-120V or 220-250 V AC). The high-current output isconnected to busbars 403 and 403′ which are connected to the array 400of heating elements located inside a defining wall 406 of box 103. Each“element” is an empty shell of usually stainless steel having similaroutline to the sections presented elsewhere in this specification.Intermediate busbars 405 connect one element to the adjoining one, allbeing wired in series. (The term “busbar” refers to a metallic connectorhaving low losses at the intended current rating). This option providesfor even heating and removes the thermal lag involved in heat transferfrom an internal heater, by heating the contact surface directly.Internal elements are not required. User and repairman safety is ensuredby use of only a low voltage. It employs the relatively high resistivityof stainless steel, as compared to copper. Although this option requiresinstallation of a step-down transformer, it avoids use of a large numberof internal bar heaters which are more likely to fail in use and hencecause some individual elements to be colder than the remainder.

An alternative heating means involves inductive heating in which eddycurrents generated within the metal surface of the melting elements bymeans of alternating magnetic fields developed from transformer primarycoils placed within cause resistive heating of the skin itself. As withthe previous heating means, this has the attraction of practicallyinstantaneous heat generation. It has the further advantage that thereis no net flow of electricity into or out of any one melting element sothat the apparatus need not be electrically bonded together. The primarycoils, preferably within each melting element, are electricallyinsulated from the melting element. The primary coils may be fed withpower at mains frequency (which may result in acoustic problems such ashumming or buzzing from magnetostrictive effects). For compactness andquietness the primary coils may be fed with high-frequency power at 20kHz or thereabouts generated within an on-board solid-state generatorsupplied with mains power. The power level is easily controllable.

The triangle or curved triangle sectional heated bar shapes of FIGS. 2and 4 will be more feasible with volume production, while the shapes ofFIG. 5 are easiest to make.

EXAMPLE 2

This Example (see 600 in FIG. 6 or FIG. 8) provides the same facilitiesas in the previous Example, and this Example also provides for a furthertask: Task 4. Receiving already-melted shortening (fat) from cookers forcleaning and eventual return, or disposal.

Cookers are usually made with valves underneath which allow the hot fatwithin to be drained away into a collecting pan beneath, so that thecooker can be cleaned out from time to time. The melter of Example 1 canbe assigned an extra function: collecting used shortening from cookersand holding it either for purifying and return to the cooker, or fortransport across the kitchen to a disposal tank. As compared to having aseparate appliance for handling used fat, this combination reduces thecapital cost of a kitchen and reduces the floor area taken up byappliances. Cost is further reduced when the same pump and the same tanksystem can be used for all the functions.

Referring to FIG. 6, one form has the melted fat/shortening collectingtray 601 extended from one lower side of the basic unit 600 on the farside from a steering handle 608. The tray may be provided with its ownset of wheels 702 although short leg-type supports against inadvertentdropping below the horizontal may suffice. The tray is shown with itsown heating means: bars 502 (here intended to raise the temperature ofthe fat as it arrives). An alternative site for a heating element is (as703 in FIG. 7) in contact with and under the inner lining 606 so thatthe fat is kept hot as long as it persists in this compartment. FIG. 7shows some details of the collecting tray. 703 is one site for a heater,bars 701 is another. It may be that a heater is not required, if theprocess of filtration can be carried out before too much time and hencecooling has elapsed, and providing that the fat as first collected isrelatively hot. A heater makes the process less complicated for anunskilled user. 704 is preferably a layer of thermal insulation such asglass fibre.

The simplest way to rejuvenate used shortening is to filter it through asieve and 603 represents a perforated intake around an inlet pipe 604leading to a pump 605 suited for sucking melted fat through the sieve. Agear pump should suffice although some forms of gear pump need primingand the inventors are aware that some users of this equipment will beunable to manage priming using hot fat. Solid material may later bescraped off the sieve 603 by the operator, bagged, and thrown out. Theoutlet 607 of the gear pump is shown here leading into internal heatedcompartment 105. It may be preferable to have one separate compartment105 for new shortening (as per Example 1) and another (105A, FIG. 8) forused shortening (as per this example and FIG. 8). Furthermore, there maybe a need to apply further rejuvenating techniques to the usedshortening, such as (1) further physical filtering means, (2) chemicalfiltering means (such as activated charcoal or a settling aid), (3)gravity-settling separation means, (4) centrifugation, or (5) flotationpurification means (such as using bubbles) to encourage removal ofdetritus. None of these means are illustrated here.

FIG. 8 shows another tray mounting means. Here the tray 601 is pivotally(with a hinge 801) mounted onto the movable appliance. 601A shows thetray half folded back and the tray would lie vertically against the sideof the appliance at 601B when fully stowed. Pipe 802 may be anextendable, flexible pipe, or a curled pipe so that it maintainsintegrity even after repeated folding and unfolding. 803 represents aspigot and drain for removing waste shortening from the heated container105A. The pump 605 and the inlet sieve are not shown in FIG. 8, forsimplicity. Nor do FIGS. 6-8 show the valves for changing the pump modefrom (mode a:) pumping out or dispensing from compartment 105 into acooker to (mode b:) retrieving fat from a cooker being emptied. Anoperator might empty a cooker from above by siphoning or suction into atemporary storage compartment, but this gives less opportunity to drainany sludge.

VARIATIONS

Improved resistive heating elements: FIG. 5 shows an array ofbox-section heating units 501, 502, 503 that may be substituted for thetriangular elements of FIGS. 1-3. One or two (505, 506 as shown)elements may be included These shapes are easier to manufacture and arestill adequate for the purpose. In FIG. 5, 500 indicates three heatingunits of an array of typically 6 units used together in one melter. Eachunit comprises a rectangular tube 1 inch wide, 2 inches high, and about2-3 feet long. Each unit is preferably made from type 304 stainlesssteel sheet 1.5 mm thick although these measurements are an illustrativeexample and may be varied, or given in integers of metric measurementsor the like. The exterior finish is unimportant as long as it iscleanable and up to food regulatory standards. The interior may be madeblackish so as to better absorb the radiated heat from the internalelements. Each unit is a sealed tube with welded-on end caps, andpreferably contains only air because if an oil suitable as a heattransfer oil was to be included there is a risk that the oil may escapesuch as through a pinhole in the weld, and then into the food (themelting and melted fat). Each unit is supported at its ends and with itssupports may from time to time bear the weight of a block of fat as itis dropped or pushed into the melter. Each unit includes 2×0.2 kWresistive heater elements for a total of 2.4 kW. The elements may bewired at the factory for example in series, in parallel, or as twogroups of parallel elements; the groups being in series, in order tomatch the rated voltage of each individual element with the local supplyvoltage. Wiring methods should allow for field replacement of unitshaving burnt-out elements.

The connection between the upper box and the lower box, past the heatingunits, may be made with a flap or other valve so that fat or odourscannot return and escape, even if the apparatus is inadvertently tippedover.

The same apparatus can be used to melt wax, such as paraffin wax orbeeswax, in situations such as foundries or electric cable manufacture,where these materials are used in quantity. It may also be used to meltbutter or fat in bakeries or other food factories, or to melt chocolate,or other foodstuffs without causing local overheating and degradation ofthe foodstuff through the Maillard reaction.

A gas or other fuel heated version could be made. Even though weconsider that electricity is a preferable source of heating energy, inpart because of the fire hazard, there will be sites where up to 2.5 kWof single-phase electricity is not available and a canister of gas(liquefied petroleum gas) is conveniently available.

INDUSTRIAL APPLICABILITY AND ADVANTAGES

Faster melting; instead of the nominal 90 minutes of prior-art fatmelters, this device takes about 20 minutes to melt a standard block.

A user cannot splash hot fat and cause injury or fire by droppinganother block into the apparatus because it will be caught, above themelted pool, by the melting heater which acts like a sieve. Deliveryinto fryers and the like without the user having to lift a container ofmelted fat up above waist height and pour. Instead, a hose and pump isused. The apparatus can be wheeled around, up to a fryer requiring fat.The thermally insulated hose and handle allows hot fat to be movedwithout causing burns to people.

Further, the capability to receive used fat allows management of acooking installation to be run more successfully. The machine canreceive fat out of a cooker so that the fat can be filtered and put backlater, or put into another cooker, and so that the cooker once empty andcooled can be cleaned.

The electric heaters and controls avoid a fire risk inherent with use ofgas or other flames. Regulated or controlled heat avoids overheating.The apparatus can be used to maintain hot fat ready for use.

The apparatus can be cleaned out from time to time by boiling a quantityof water, optionally including surfactants or other acceptablematerials, in the or each lower container or tank. Hence the apparatusshould be able to maintain acceptable regulatory standards ofcleanliness.

Finally, it will be understood that those of skill will appreciate thatvarious modifications, additions, known equivalents, and substitutionsto the described embodiments are possible without departing from thescope and spirit of the invention as set forth in the following claims.

1. A powered appliance to service deep-fry cookers in a kitchen with asupply of liquid shortening (as herein defined) from time to time, andremove used liquid shortening from time to time, characterised in thatthe appliance includes internal means for melting a block of solidshortening, means for holding the melted shortening in a first internalheated chamber, and means for supplying a cooker with the meltedshortening from the first internal heated chamber: the appliance alsobeing provided with wheels so that it can be pushed up to the cooker tobe serviced.
 2. An appliance as claimed in claim 1, furthercharacterised in that the internal means for melting a block of solidshortening employs a series of transverse bars forming a top surface forthe internal heated chamber, each bar being internally heated andcapable of bearing a solid block of shortening during a melting process.3. An appliance as claimed in claim 2, further characterised in thateach bar is heated by an internal electric resistive element.
 4. Anappliance as claimed in claim 2, further characterised in that each baris ohmically heated by passage of a heavy current at low voltage throughthe surface material of the bar.
 5. An appliance as claimed in claim 2,further characterised in that each bar is ohmically heated bycirculation of eddy currents within the bar, the currents being inducedby an alternating magnetic field developed in proximity to each bar. 6.An appliance as claimed in claim 2, further characterised in that theappliance includes means to receive hot used, molten shortening frombelow a cooker into a protruding heated container, the applianceincluding a pump to lift the used shortening from the protruding heatedcontainer into the first internal heated container: the appliance alsobeing provided with wheels so that the protruding heated container canbe pushed under the cooker to be emptied.
 7. An appliance as claimed inclaim 6, further characterised in that the appliance includes a secondinternal heated chamber reserved for receiving and holding usedshortening: the first internal heated chamber of the appliance beingreserved for use with new or unused shortening.
 8. An appliance asclaimed in claim 6, further characterised in that the appliance includesa filter through which the used cooking oil is received so that filtereddetritus may be removed from the used shortening and discarded, so thatthe shortening may be re-used if acceptable.
 9. An appliance as claimedin claim 7, further characterised in that the appliance includes afilter through which the used cooking oil is received so that filtereddetritus may be removed from the used shortening and discarded, so thatthe shortening may be re-used if acceptable.